[移动开发]iOS-Swift DateExtension(扩展)

实现的功能：

1. 获取当前日期的年、月、日

2. 获取指定月份的天数

import Foundation

class FormatTime24 {
    var year: Int?
    var month: Int?
    var day: Int?
}

extension Date {
    // MARK: 获取当前年 月 日
    static var now: FormatTime24 {
        get {
            let n = FormatTime24()
            
            let date = Date()
            let calendar = Calendar.current
             
            n.year = calendar.component(.year, from: date)
            n.month = calendar.component(.month, from: date)
            n.day = calendar.component(.day, from: date)
            
            return n
        }
    }
    
    // MARK: 获取指定年月 月份的天数
    static func getDaysInMonth(year: Int, month: Int) -> Int {
        var startComps = DateComponents()
        
        startComps.year = year
        startComps.month = month
        startComps.day = 1
        
        var endComps = DateComponents()
        
        endComps.year = year
        endComps.month = month + 1
        if month == 12 {
            endComps.year = year + 1
            endComps.month = 1
        }
        endComps.day = 1
        
        let calendar = Calendar.current
        
        let dayRange = calendar.dateComponents([.day], from: startComps, to: endComps)
        
        return dayRange.day ?? 0
    }
}